Severino de Paiva Sobrinho

Germinação e produção de mudas de tamboril (Enterolobium Contortisiliquum (Vell.) Morong) em diferentes substratos

The Enterolobium contortisiliquum (Vell.) Morong. is a tree of Brazilian origin, occurring from north to south, from the family Leguminosea-Mimosoideae. The objective of this study was to evaluate the effect of different substrates on germination and seedling growth of tamboril. The treatments were: T1 - soil, T2 - soil + manure, T3 - soil + carbonized rice straw and T 4 - soil + manure + carbonized rice straw. The evaluated variables included emergence percentage, emergence speed index, plant height, number of leaves, stem diameter, weight of the fresh and dry matter on the aerial parts and weight of fresh and dry root. The experimental design was completely randomized with four treatments and five replications of 20 seeds. The emergence and the emergence speed index had better performance in substrates soil +manure and soil + carbonized rice straw. The characteristics of the seedlings growh at 120 days after sowing has positively influenced by the presence of manure in the composition of the substrate.

CARACTERIZAÇÃO MORFOLÓGICA DE FRUTOS, SEMENTES, PLÂNTULAS E PLANTAS JOVENS DE MUTAMBA (Guazuma ulmifolia Lam. - STERCULIACEAE) 1

RESUMO – A Guazuma ulmifolia Lam. e uma especie arborea pioneira de ocorrencia natural em quase todo o Brasil, desde a Amazonia ate o Parana. Pertence a familia Sterculiaceae, sendo recomendada para recuperacao de areas degradadas. O objetivo deste trabalho foi descrever os caracteres morfologicos dos frutos, sementes, plântula e planta jovem. No fruto foram observados: forma, coloracao, dimensoes, textura, deiscencia, e o numero de sementes por fruto. Na semente foram observados: coloracao, peso de 1000 sementes, forma, tegumento, embriao e endosperma. O estadio de plântula foi considerado ate o momento em que tinha apenas os cotiledones e a partir da emissao de folhas passou a ser considerada planta jovem. Os aspectos vegetativos descritos e ilustrados foram: raiz primaria, raizes secundarias e terciarias, hipocotilo, epicotilo, cotiledones, caule, folhas e gema apical. Fruto e uma capsula loculicida globoso, de coloracao preta, com faixas estreitas e superficie muricada. Semente de coloracao acinzentada e formas variadas, envolta pela testa que quando umedecida torna-se gelatinosa. Embriao axial e continuo; com cotiledones foliaceos, plicados e que apos a emergencia sao arredondados, verdes e com nervuras. Apos a emergencia o hipocotilo e a raiz primaria sao brancos e cilindricos, mas com passar do tempo se tornam mais escuros. Caule de coloracao verde-escura; folhas pecioladas, com nervura principal e secundaria; limbo com margem dentada.

Avaliação da qualidade fisiológica de sementes de feijão-caupi pelo teste de condutividade elétrica

Evaluation of cowpea seed quality by electrical conductivity The electrical conductivity of the seed soaking solution is a procedure recommended for the evaluation of vigor in pea and soybean seeds. However, it was not so well established in other species. The objective of this work was to evaluate their effects on physiological quality of cowpea seeds. Four batches of cowpea seeds were tested for germination, first count of germination, germination percentage, emergence percentage, rate of emergence, radicle and variations in electrical conductivity (temperature 25 °C; volumes of 75 mL and 100 mL of water, 25 and 50 seeds, and 2, 4, 8, 12 and 24 hours periods). The experimental design was a completely randomized with four replicates for each treatment. Based on these results, it was found that the electrical conductivity test was efficient in the separation of seed lots according to their vigor levels.

Superação da dormência em sementes de mutamba (guazuma ulmifolia lam. - sterculiaceae)

Guazuma ulmifolia Lam. have seed with high water impermeability which impairs germination. The effect of the immersion time (0, 4, 8, 12 and 16 minutes) of Guazuma ulmifolia Lam. in concentrated sulfuric acid, and water at 60oC for 0, 4, 8, 12 and 16 minutes were evaluated for emergency and vigor (start of the emergency and speed index). The experiment was carried out in the Biology Laboratory, in a completely randomized design in 2 x 5 factorial (2 pre-emergency treatment and 5 immersion times), with three replicates of the 20 seeds. The pre-conditioning of seeds in sulphuric acid as well as in water at 60oC was efficient in breaking the seed dormancy and also for increasing the emergence percentage and speed, and reduction of the time for onset of emergence. The efficiency of this chemical treatment with sulphuric acid was obtained with a immersion time of 8 minutes, while in the physical treatment with water at 60oC, the efficiency was obtained with immersion time of 16 minutes.